Constraints on Meteoric Smoke Composition and Meteoric Influx Using SOFIE Observations With Models. Issue 24 (22nd December 2017)

• Record Type: Journal Article
• Authors: Hervig, Mark E.; Brooke, James S. A.; Feng, Wuhu; Bardeen, Charles G.; Plane, John M. C.
• Is Part Of: Journal of geophysical research. Volume 122:Issue 24(2017)
• Page Start: 13, 495
• Page End: 13, 505
• Publication Date: 2017-12-22
• Subjects: meteoric smoke composition -- meteoric influx -- SOFIE -- WACCM; Atmospheric physics -- Periodicals; Geophysics -- Periodicals; 551.5
• DOI: 10.1002/2017JD027657
• Languages: English
• ISSNs: 2169-897X

Abstract

Abstract: The composition of meteoric smoke particles in the mesosphere is constrained using measurements from the Solar Occultation For Ice Experiment (SOFIE) in conjunction with models. Comparing the multiwavelength observations with models suggests smoke compositions of magnetite, wüstite, magnesiowüstite, or iron‐rich olivine. Smoke compositions of pure pyroxene, hematite, iron‐poor olivine, magnesium silicate, and silica are excluded, although this may be because these materials have weak signatures at the SOFIE wavelengths. Information concerning smoke composition allows the SOFIE extinction measurements to be converted to smoke volume density. Comparing the observed volume density with model results for varying meteoric influx (MI) provides constraints on the ablated fraction of incoming meteoric material. The results indicate a global ablated MI of 3.3 ± 1.9 t d −1, which represents only iron, magnesium, and possibly silica, given the smoke compositions indicated here. Considering the optics and iron content of individual smoke compositions gives an ablated Fe influx of 1.8 ± 0.9 t d −1 . Finally, the global total meteoric influx (ablated plus surviving) is estimated to be 30 ± 18 t d −1, when considering the present results and a recent description of the speciation of meteoric material. Key Points: Meteoric smoke in the mesosphere can be composed of magnetite, wüstite, magnesiowüstite, or iron‐rich olivine Smoke compositions of pure pyroxene, hematite, iron‐poor olivine, magnesium silicate, and silica are excluded Global meteoric influx estimates are 3.3 t d −1 for ablated material only and 30 t d −1 for the total influx